6 - STRUCTURAL SEX DIFFERENCES Flashcards
1
Q
corpus callosum
one explanation of hemispheric lateralisation
A
assumptions:
- corpus callosum as a whole larger in women?
- more connections between hemispheres?
- explain less lateralised brain
- splenium more bulbous in women?
- isthmus relatively larger in women? (relative to brain size)
- but mixed evidence - could be due to measurement methods
2
Q
overall brain size
one explanation of hemispheric lateralisation
A
-
3
Q
cortical structures
other candidate structures for hemispheric specialisation
A
- posterior temporal cortex - higher neuron density in women?
- temporal plane (roof of temporal lobe - different size in each hemisphere) - larger size asymmetry in men?
evidence not very convincing
4
Q
subcortical structures
other candidate structures for hemispheric specialisation
A
- sub cortical candidate structures
- INAH-3 of hypothalamus larger in men?
- cut through anterior hypothalamus
- Levay says this plays a similar role in humans as the SDN-POA un rats
- homosexual male and female similar size
- but Levay used a small sample size and homosexuals died of AIDs which could affect brain
5
Q
information:
no clear evidence for gender difference in the anatomy of the forebrain
- but anatomical differences might be too subtle to be detected easily and reliably
- perhaps differences in local patterns of connectivity? (but can assess patterns of synaptic connections)
- or differences in relative density of different neuron types in some brain areas?
- or differences at the level of neurotransmitter and receptor molecules?
A
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6
Q
brain mosaic
A
Joel et al (2015)
- several brain structures so show sex difference on average
- but differences not distributed in an internally consistent way (within the individual)
- have different levels of being ‘male-typical’ or ‘female-typical’
- same for the body parts
- no specific male or female pattern
- very few have a purely male or female brain pattern
